.popup {
  display: none; 
  position: fixed; 
  z-index: 1000; 
  left: 0; 
  top: 0;
  width: 100%; 
  height: 100%; 
  background-color: rgba(0,0,0,0.6);
}

.popup-content {
  background: #fff;
  margin: 10% auto;
  padding: 20px;
  width: 400px;
  border-radius: 10px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.3);
  position: relative;
}

.chiudi {
  color: #aaa;
  font-size: 28px;
  font-weight: bold;
  position: absolute;
  right: 15px;
  top: 10px;
  cursor: pointer;
}

.chiudi:hover {
  color: #000;
}